Put the butter, coconut milk, sugar, flour, eggs, coconut extract (if using) and desiccated coconut in a large bowl and beat with an electric whisk until combined. Scrape into the prepared tin and level the top with a spatula or the back of a spoon. Bake for 55 mins-1 hr, or until the cake is risen and golden brown and a skewer inserted into the middle comes out clean. If any wet cake mixture clings to the skewer, bake for another 5-10 mins, then check again. Leave to cool in the tin for 10 mins, then lift the cake out onto a wire rack, using the parchment to help you. Leave to cool completely. The cooled cake will keep in the freezer, well wrapped, for up to two months.